Vat dye.



1 PAN WILHELM BAUER, ALFRED HERRE, Ann utmost MAYER, or ELBERFELD,GERMANY, ASSIGNORS :ro- FARBENFAIBRIKENVORM. FRIEIJR. BAYER'&'CQ., orELBERFELD,

GERMANY, A coaroaarrou or GERMANY.

?atented Sept. 30, 1913.

VAT DYE.

1,074,405. Specification-of Letters Patent. No Drawing.

Application filed February 11', 1913. Serial 1%. 74?,699.

halogen The new dyes are in a dry state reddishbrown crystals with ametallicluster which are soluble in hot nitrobenzene with a redcoloration. They yield with hydrosulfite and caustic soda lye yellowvats dyeing cotton after exposure to air red shades fast to chlorin andto light.

In order to illustrate the new process more fully the following exampleis given, the parts being by weight :-220 parts of 5.7- dichloroisatinare dissolved in 5000 parts of hot glacial acetic acid, a solution of167 parts of 6-chloro-indoxyl in 500 parts of glacial acetic acid andthen 100 parts of concent-rated. hydrochloric acid are added, Theresulting mixture is heated during one hour on the water bath. Thedyestufi' which has separated is filtered off after cooling, washed anddried. It has most probably the following formula: p

' (tr e O 'c1 1-IH ot H/\/ red shades fast to chlorin, washing andlight. Similar dyes are obtained on using instead of fi-chloro-indoxyldescribed in the example 6-methyl-, fi-alkoxyor 6-thioal- CO /\/ha1ogeno 6 We have found that new and valuable vat dyestuffs canbe obtained bycondensing indoxyls which are substituted in position 6 with5.7-dihalogenated isatins. The reaction proceeds most probably inaccordance with the following equation:

halogen+H O l I l halogen (R meaning substituent.)

ed formula: v

/\ ha1ogen alogen R meaning a substituent,

which dyes are in a dry state reddish-brown crystals with a metallicluster soluble in hot nitrobenzene generally with a red coloration; andwhich yield with hydrosulfite and caustic soda lye vats dyeing cottonred shades remarkable for their fastness to chlorin and to light,substantially as described.

2. The new producthaving most probably the formula being a vat'dyederivable from 5.7 -'dichloroisatin and G-chloroindoxyl, which is in adry state a brown crystalline powder with a metallic luster, soluble inconcentrated sulfuric set our hands in the presence of tivo subacid witha brownish-red color and in monoscribing Witnesses.

hydrated sulfuric acid with a reddish-violet WILHELM BAUER. [L. s.]color; and dyeing cotton from the hydro- ALFRED HERRE. [L.s.] sulfitevat in red shades fast to chlorin, RUDOLF MAYER. [L.s.] washing andlight, substantially as de- Witnesses: scribed.

. HELEN NUEER, In testimony whereof We have hereunto ALBERT NUEER.

